Give server() consumers the onRequest hook the docs promise (#86)

* Regression tests for an onRequest hook on server()

* Compose the application's onRequest hook into server() past bind

* Document the server's onRequest hook and record the composition decision

* Pin that a re-bind and a pre-bind unbind never reach the hook, and that a non-function hook is refused at startup

* Keep every bind and all pre-bind traffic out of the application's hook

* Make the hook's published promises exact, and record the src layout deferral

* Trim the record to what the tests do not already forbid

* Pin that nothing answers a request whose hook failed

* Answer nothing for a request whose hook failed, on both surfaces alike

* State the hook's failure policy as it now behaves

* Name the request a failed handler left unanswered, and say what a wedged hook reports

src/sms.ts

@@ -112,7 +112,7 @@ function answeredOnArrival(
 
 	if (options.status !== undefined && options.status !== 'ESME_ROK') {
 		return Promise.resolve({
-			err: new Error('Its segments were answered as they arrived, so there is nothing left to refuse; refuse a segment from onRequest instead'),
+			err: new Error('Its segments were answered as they arrived, so there is nothing left to refuse; refuse a segment from the onRequest option instead'),
 		});
 	}